Unless someone wants to go to court over this (and no one will) this whole discussion is completely ridiculous.
People have. Not necessarily for minecraft mods, but definitely for infringement, even infringement of a non commercial product. And don't pay attention to those claims (The pack plus, or whatever they're called) that something has to be commercial to matter.
The thing to remember though is that copyright is entirely about distribution. If somebody is claiming something that isn't directly distribution, they're not talking about copyright law. For example, license use agreements are _not_ copyright law. They're also much murkier on their actual enforcement value.
It's debatable if you even have copyright to a Minecraft mod (that's a grey area)
Oh it is absolutely not a grey area. Berne convention is worldwide (or at least, those countries that didn't sign have problems with electricity) and applies an automatic copyright to all works. Including this very post.
then there's the point that the mods are FREE software and you're completely allowed to mirror that
You are absolutely not allowed to re-distribute something just because the author distributes it for free. In the US, in addition to the monetary loss (which granted, would be zero), there is a $200 to $150,000 potential penalty, _per_infraction_. In this context, an infraction would be per download. And before even that, a judge is going to issue an injunction, and violation of that injunction can absolutely result in jailtime.
Also, again in the US, the legal fees of copyright cases for both parties are paid for by the infractor if they lose, but the author only pays their own fees if they lose. There is thus very little pressure to _not_ file.
THEN there is the point whether or not a config file is considered something that you can even have copyright on.
They can. They do. It's automatic.
So unless you can prove with jurisprudence that this is the case (and don't bring up the Berne convention, it's completely irrelevant what they wrote up in 1886 since it predates modern copyright laws which have complete sections on software) this whole discussion is completely pointless.
I should have read this part first. You are too far out in fantasy land to even hold this conversation with. The Berne convention is in full force and is affecting your every day life... everyday.